Hi, Yue-Wen, You need to set occupations='fixed' for insulator. 'Smearing' is for metal.
Best regards, Ding-Fu *Ding-Fu Shao, Ph. D.* *Department of Physics and Astronomy, University of Nebraska-Lincoln* *Lincoln, NE **68588-0299* *Email: [email protected] <[email protected]>* 2016-04-22 4:43 GMT-05:00 Yue-Wen Fang <[email protected]>: > Dear all, > > I calculated a MgO slab model with two* symmetrical* interface using 3 > different DFT codes using plane wave method. The other two shows this slab > is an insulator, and the results are almost completely same. > > However, pwscf calculation show it is a metal with an unexpected Fermi > shift in the density of states although the shape of DOS is similar to > those obtained from other DFTcodes. I think this is caused my incorrect > settings, but I haven't found what specific factor causes this error. > > The scf and nscf input files are shown in the last part, hopefully experts > could give some suggestions. Many thanks. > > *PS:* > Because it is just a test, I only used about 6 Angstrom in this model. I > checked the potential in every DFT code, there is no slope of potential in > vacuum, which indicates there is no unexpected artificial field is induced. > > > *SCF calculation input:* > > &control > calculation = 'scf', > verbosity = 'high', > restart_mode = 'from_scratch', > prefix = 'mgo', > tstress = .false., > tprnfor = .false., > pseudo_dir = '.', > outdir = '.' > wf_collect=.true. > / > &system > ibrav=0, nat=6, ntyp=2, > ecutwfc=25, > ecutrho=300, > occupations='smearing', > smearing='gaussian', > degauss=0.001, > / > &electrons > diagonalization='david', > mixing_mode = 'plain', > mixing_beta = 0.7, > conv_thr = 1.0d-7, > / > ATOMIC_SPECIES > Mg 24.305000 Mg.pbe-nsp-bpaw.UPF > O 15.999400 O.pbe-van_ak.UPF > ATOMIC_POSITIONS crystal > Mg 0.000000 0.000000 0.370955 > Mg 0.500000 0.500000 0.500000 > Mg 0.000000 0.000000 0.629045 > O 0.500000 0.500000 0.370955 > O 0.000000 0.000000 0.500000 > O 0.500000 0.500000 0.629045 > K_POINTS {Automatic} > 7 7 1 0 0 0 > CELL_PARAMETERS bohr > 5.627166 0.000000 0.000000 > 0.000000 5.627166 0.000000 > 0.000000 0.000000 30.834283 > > > *NSCF calculation input:* > > &control > calculation = 'nscf', > verbosity = 'high', > restart_mode = 'from_scratch', > prefix = 'mgo', > tstress = .false., > tprnfor = .false., > pseudo_dir = '.', > outdir = '.' > wf_collect=.true. > / > &system > ibrav=0, nat=6, ntyp=2, > ecutwfc=25, > ecutrho=300, > occupations='tetrahedra', > / > &electrons > diagonalization='david', > mixing_mode = 'plain', > mixing_beta = 0.7, > conv_thr = 1.0d-7, > / > ATOMIC_SPECIES > Mg 24.305000 Mg.pbe-nsp-bpaw.UPF > O 15.999400 O.pbe-van_ak.UPF > ATOMIC_POSITIONS crystal > Mg 0.000000 0.000000 0.370955 > Mg 0.500000 0.500000 0.500000 > Mg 0.000000 0.000000 0.629045 > O 0.500000 0.500000 0.370955 > O 0.000000 0.000000 0.500000 > O 0.500000 0.500000 0.629045 > K_POINTS {Automatic} > 11 11 2 0 0 0 > CELL_PARAMETERS bohr > 5.627166 0.000000 0.000000 > 0.000000 5.627166 0.000000 > 0.000000 0.000000 30.834283 > > -- > > ------------------------------------------------------------------------------------------------------------ > Yue-Wen FANG, PhD student > East China Normal University <http://english.ecnu.edu.cn/>, China > Japan Fine Ceramics Center, Japan > > > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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